LOCATION ZEN WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Calciargidic Argixerolls
TYPICAL PEDON: Zen silt loam, dry cropland, on a 5 percent southwest-facing slope at 2,750 feet elevation. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures).
Ap--0 to 9 inches; brown (10YR 5/3) silt loam, very dark brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular and vesicular pores; 2 percent sand-size pumice, 0.5 to 2 mm in size; slightly acid (pH 6.5); gradual smooth boundary. (6 to 10 inches thick)
AB--9 to 15 inches; yellowish brown (10YR 5/4) silt loam, very dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine and fine roots; common fine tubular and vesicular pores; 2 percent sand-size pumice 0.5 to 2.0 mm in size; neutral (pH 7.2), clear smooth boundary. (4 to 7 inches thick)
Bt--15 to 27 inches; yellowish brown (10YR 5/4) silt loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few fine and very fine vesicular pores; 5 percent pebbles; 2 percent durinodes; trace of sand-size pumice; common faint clay films on faces of peds; slightly alkaline (pH 7.8), clear smooth boundary. (4 to 14 inches thick)
Btk--27 to 36 inches; yellowish brown (10YR 5/4) loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; few very fine roots; common fine and medium vesicular and irregular pores; 5 percent pebbles; 2 percent durinodes; many distinct clay films on faces of peds; few fine irregular lime masses; strongly effervescent; moderately alkaline (pH 8.0), abrupt wavy boundary. (6 to 10 inches thick)
2R--36 inches; basalt with thin lime coatings.
TYPE LOCATION: Douglas County, Washington, about 12 miles south of Waterville, Washington, about 1,300 feet north and 1,300 feet east of the southwest corner of section 23, T. 23 N., R. 22 E. (Latitude 47 degrees 28' 10" N, Longitude 120 degrees 02' 25"W)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 52 degrees F. These soils are usually dry in the moisture control section for 105 to 120 cumulative days when the soil temperature is above 41 degrees F. The mollic epipedon is 10 to 20 inches thick. The particle-size control section averages 22 to 28 percent clay, 5 to 15 percent coarse fragments and is more than 15 percent sand that is coarser than very fine sand. There is 1 to 5 percent sand-size pumice in the solum. Depth to secondary carbonates is 14 to 30 inches and there is 3 to 15 percent calcium carbonate equivalent. Depth to bedrock is 20 to 40 inches.
The Ap or A horizon has value 4 or 5 dry and 3 or 4 moist. Chroma is 2 or 3 dry or moist. It is slightly acid to slightly alkaline.
The AB horizon has value 4 or 5 dry and 3 or 4 moist. Chroma is 2 or 3 moist and 3 or 4 dry. It is neutral or slightly alkaline.
The Bt horizon has value 4 through 6 dry and 3 or 4 moist. Chroma is 3 or 4 dry or moist. It is neutral to moderately alkaline. Texture is silt loam, silty clay loam or clay loam with 0 to 5 percent coarse fragments.
The Btk horizon has value 4 through 6 dry and 3 through 5 moist. Chroma is 3 or 4 dry or moist. It is slightly to strongly alkaline. Texture is silt loam, loam, clay loam, silty clay loam or gravelly loam with 5 to 20 percent coarse fragments.
COMPETING SERIES: These are the Axford, Babbington, Benwy, Bidwell, Brogan (T), Caliralls, Drybed, and Haw series. Axford, Babbington, Benway, Bidwell, Brogan, Caliralls, Drybed, and Haw soils are more than 40 inches deep.
GEOGRAPHIC SETTING: Zen soils are on hill slopes, ridges and benches of dissected basalt plateaus at elevations of 1,500 to 3,300 feet. These soils formed in a mantle of young loess over older loess and slope alluvium above basalt bedrock. Slopes are 0 to 45 percent. Average annual precipitation is 9 to 12 inches. These soils are in a semiarid climate with warm dry summers and cool moist winters. Average January temperature is 27 degrees F.; the average July temperature is 71 degrees F.; and the average annual temperature is 48 to 50 degrees F. Frost-free season is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alstown, Argabak, Bakeoven, Benwy, Horseflat, Lickskillet, Ralls, Renslow and Willis soils. Alstown soils are on plateaus and have less than 18 percent clay in the control section and have a duripan at 20 to 40 inches. Argabak, Bakeoven and Lickskillet soils are on plateaus and are less than 20 inches to bedrock. Benwy, Ralls and Renslow soils are on hills and are more than 40 inches deep. Horseflat soils are on hillslopes and are more than 35 percent coarse fragments and are shallow to bedrock. Willis soils are on uplands and are moderately deep to a duripan and have less than 18 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained, very slow to rapid runoff; moderate permeability.
USE AND VEGETATION: Dryland small grain production, livestock grazing, watershed and wildlife habitat. Native vegetation is bluebunch wheatgrass, Sandberg bluegrass, and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: Central Washington. These soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Chelan County, Washington, 1968.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 15 inches, an argillic horizon from 15 to 36 inches, secondary carbonates from 27 to 36 inches and a lithic contact at 36 inches. The particle-size control section is the zone from 15 to 35 inches (upper 20 inches of the argillic horizon).